JP2018067699A - Gas permeable joined body of sealed type electrochemical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas permeable joined body of a sealed type electrochemical device, which is arranged so that a predetermined amount of gas generated in a closed container with an electrode element and an electrolyte contained therein is allowed to permeate the gas permeable joined body, and the predetermined amount of gas is then discharged to outside the closed container.SOLUTION: In a gas permeable joined body of a sealed type electrochemical device according to the present invention, a junction layer 5 is formed on at least one of a first mold 2 and a second mold 3; the first mold 2 is joined to the second mold 3 through the junction layer 5, thereby forming a constituent member of a closed container; the junction layer 5 is partially removed by a predetermined amount so as to communicate to inside the closed container to form a minute gap portion 5A in a joint face of the first mold 2 and the second mold 3 joined to each other, preferably the minute gap portion 5A of which the helium leak velocity becomes 1.0×10-1.0×10Pa m/s under a pressure of 0.1 MPa(G); and the minute gap portion 5A makes a gas permeable path for discharging gas generated in the closed container to outside the closed container.SELECTED DRAWING: Figure 1

Description

The present invention relates to a gas permeable joined body of a sealed electrochemical device containing an electrode element and an electrolyte.

In a closed electrochemical device such as a capacitor or lithium battery in which an electrode element and electrolyte are housed in a sealed container, the battery may be repeatedly charged and discharged, left at high temperatures, short-circuited, overcharged, or reverse charged. When the electrolyte is decomposed, gas such as hydrogen gas or carbon dioxide gas is generated in the sealed container, and the pressure in the sealed container suddenly increases due to accumulation of the gas in the sealed container. As the sealed container expands and the sealed container bursts, the sealed electrochemical device is damaged, so that the generated gas is appropriately discharged out of the sealed container so that the generated gas does not accumulate in the sealed container. A sealed electrochemical device having a function is desired.

The cylindrical part which opened the through-hole of the 1st molded object is made hollow, the gas permeation | separation partition part equivalent to a 2nd molded object is provided in this hollow, and the gas permeation | transmission which made this gas permeable partition part the gas permeation | transmission path At least one surface of the upper and lower surfaces of the gas permeable partition portion in the hollow of the cylindrical portion by providing a gas permeable surface layer sheet, which is a filter and has a gas permeable amount larger than that of the gas permeable partition portion, separated from the gas permeable partition portion Patent Document 1 proposes a gas permeation filter that forms a space in the surface and prevents moisture from permeating and has good gas permeability.

However, in the gas permeable filter of Patent Document 1, it is necessary to form a gas permeable partition part that functions as a gas permeable filter that hardly permeates moisture and has good gas permeability in the hollow cylindrical part.

In addition, a liquid port plug having an exhaust hole for discharging the gas inside the battery generated during charging is attached to the electrolyte port, and the exhaust port of the liquid port plug is covered with an acid-resistant resin sheet. Patent Document 2 proposes a lead storage battery in which the upper portion of the spout and the gas discharge path are formed at portions where no adhesive or adhesive is applied.

However, in the lead-acid battery of Patent Document 2, even if the liquid plug corresponds to the second molded body that closes the through hole of the first molded body, no flow path is formed in the liquid plug itself. In addition to the liquid spigot, an acid-resistant resin sheet that covers the liquid spigot is necessary for forming the flow path.

Patent Document 3 discloses that in a sheet-like lithium battery having a structure in which a separator and an electrolyte are interposed between a positive electrode sheet and a negative electrode sheet and sealed with an outer sheet or an outer film, the outer film is thermally fused. There has been proposed a sheet-like lithium battery in which a narrow safety valve portion is formed by forming an unfused portion in a part of the sealed portion.

However, in the sheet-like lithium battery of Patent Document 3, when the pressure inside the battery rises due to overcharging or high temperature, the unattached portion breaks the outer film, and the gas inside the battery Is not led to the outside, and is not a gas permeation path structure for discharging the gas to the outside by a predetermined amount.

Japanese Patent Laying-Open No. 2006-163875 JP 2009-2108030 A JP 2003-132868 A

In order to solve the above-mentioned problems, the present invention allows gas generated in a sealed electrochemical device that allows a predetermined amount of gas generated in a sealed container containing an electrode element and an electrolyte to pass through and is discharged out of the sealed container. An object is to provide a joined body.

The gas permeable bonded body for a sealed electrochemical device according to claim 1 of the present invention is formed by forming a bonding layer on at least one of the first molded body and the second molded body and interposing the bonding layer via the bonding layer. The first molded body and the second molded body are joined to form a component of the sealed container, and a predetermined amount is removed so that a part of the joining layer is communicated with the inside of the sealed container. The molded body and the second molded body are joined to form a minute gap on the joining surface, and the minute gap serves as a gas permeation path for discharging the gas generated in the sealed container to the outside of the sealed container. It is characterized by doing so. The gas permeable assembly of the sealed electrochemical device according to claim 2 is the gas permeable assembly according to claim 1, wherein the minute gap portion has a pressure of 0.1 MPa (G) and a helium leak rate of 1.0 × 10 6. It is a gas permeation path of ^{−2 to} 1.0 × 10 ⁻⁵ Pa · m ³ / s. The gas-permeable assembly of the sealed electrochemical device according to claim 3 is the first or second molded body according to claim 1 or 2, wherein the first molded body has a through hole. The through-hole is closed by bonding through the bonding layer, and a sealing body that is a constituent member of a sealed container is formed by the first molded body and the second molded body, and the bonding layer The first molded body and the second molded body are joined by removing a predetermined amount so as to communicate with the through hole and joining the first molded body and the second molded body. A small gap is formed on the surface.

The gas-permeable bonded body of the hermetic electrochemical device of the present invention has a bonding layer formed on at least one of the first molded body and the second molded body, and the first molded body and the first molded body are interposed through the bonding layer. By joining the two molded bodies, a constituent member of the sealed container is formed, and a predetermined amount is removed so that a part of the bonding layer communicates with the inside of the sealed container, and the first molded body and the second molded body are removed. The molded body is joined and the helium leak rate becomes 1.0 × 10 ^{−2 to} 1.0 × 10 ⁻⁵ Pa · m ³ / s at a pressure of 0.1 MPa (G), for example. By forming a minute gap, it forms a gas permeation path that allows gas to permeate but does not allow moisture such as water vapor to permeate, and a simple structure that removes a predetermined amount of the joined body. A gas permeation path that exhausts the gas generated inside to the outside of the sealed container is obtained. It is.

It is AA sectional drawing of Embodiment 2 in Embodiment 1 of this invention. 1 is a plan view of a gas permeable joined body of a sealed electrochemical device according to Embodiment 1 of the present invention. It is sectional drawing which shows the joining operation state of the gas permeable conjugate | bonded_body of a sealed electrochemical device in Embodiment 1 of this invention. It is explanatory drawing of the surface treatment which forms a micro clearance gap in the surface of the 2nd molded object of this invention. It is BB sectional drawing of Embodiment 6 in Embodiment 2 of this invention. It is a top view of the gas permeable conjugate | bonded_body of a sealed electrochemical device in Embodiment 2 of this invention. It is a rear view which shows the state which removed predetermined amount the joining layer with the 2nd molded object in Embodiment 2 of this invention. It is CC sectional drawing of FIG. 9 in Embodiment 3 of this invention. It is a top view of the gas permeable conjugate | bonded_body of a sealed electrochemical device in Embodiment 3 of this invention. It is sectional drawing which shows the sealed electrochemical device using the gas permeable conjugate | bonded_body of the sealed electrochemical device of Embodiment 1-3 of this invention. It is a side view which shows the sealed electrochemical device which differs in Embodiment 4 of this invention. It is a top view of the joint surface in the gas permeable conjugate | bonded_body of a sealed electrochemical device in Embodiment 4 of this invention. It is DD sectional drawing of Embodiment 12 in Embodiment 4 of this invention.

(Embodiment 1)
1 to 4, a gas-permeable joined body of a sealed electrochemical device in which a flat plate-shaped first molded body having a circular through hole and a columnar second molded body are incorporated in the through-hole. The structure of will be described.

In FIG. 1, a gas permeable joined body 1 includes a flat plate-shaped first molded body 2 having a through-hole 4 and a columnar second molded body 3 formed in the through-hole 4, and is a part of a sealed container. Is configured. In order to configure this sealed container, the through hole 4 formed in the first molded body 2 is closed with the second molded body 3. Examples of the material of the first molded body 2 include synthetic resin materials such as polyphenylene sulfide (PPS) resin and polypropyne (PP) resin, and metal materials such as aluminum (including alloys). Moreover, the 2nd molded object 3 is formed in the column shape, and as shown in FIG. 3, it inserts in the through-hole 4 of the 1st molded object 2, and is made to plug. The material of the second molded body 3 is made of the same material as that of the first molded body 2, and a bonding layer 5 is formed on the outer peripheral surface thereof. The bonding layer 5 includes a mercapto group, a thiocarbonyl group, and the like. Group, cyano group, isocyanate group, amino group, ammonium group, pyridinium group, azinyl group, carboxyl group, benzotriazole group, triazine thiol group, etc. Examples of the resin bonding layer include layers and epoxy resin materials. A bonding layer 5 is formed so as to be tightly bonded to the inner peripheral surface of the through hole 4 of the first molded body 2. When the second molded body 3 is thus inserted into the through hole 4 of the first molded body 2, the second molded body 3 is inserted into the through hole 4 of the first molded body 2 through the bonding layer 5. By tightly bonding, the through hole 4 of the first molded body 2 becomes a closed liquid mouth plug 6 and maintains the sealing property of the sealed container.

The hermetically sealed container is a sealed container of a sealed electrochemical device such as a capacitor having an electrolyte solution or lithium as described later. In this kind of hermetically sealed container, the gas generated inside (the lower surface in FIG. 1) is shown in FIG. It is necessary to discharge from the minute gap portion 5A shown to the outside of the container in the direction of the arrow, and the gas permeable bonded body 1 has a bonding layer 5 for tightly bonding the first molded body 2 and the second molded body 3 to each other. A gas permeation path for discharging the gas out of the sealed container is provided. The gas permeation path allows gas to permeate by removing a predetermined amount so that a part of the bonding layer 5 communicates with the inside of the sealed container to form a predetermined minute gap 5A, but allows moisture such as water vapor to permeate. The gas permeation path is configured so as not to be allowed to occur. FIG. 4 shows an example of a method for forming this gas permeation path.

FIG. 4 shows a minute gap formed on the joint surface between the first molded body 2, 21 and the second molded body 3, 30, 31, 300 applied to the first embodiment and the second to fourth embodiments. The formation method of 5A is shown

In FIG. 4, a mercapto group is formed on the surface of the second molded body 3, 30, 31, 300 that is one of the joint surfaces of the first molded body 2, 21 and the second molded body 3, 30, 31, 300. , A thiocarbonyl group, a cyano group, an isocyanate group, an amino group, an ammonium group, a pyridinium group, an azinyl group, a carboxyl group, a benzotriazole group, a triazine thiol group, etc. A bonding layer 5 composed of a thin film layer of an agent is formed, a part of the bonding layer 5 is irradiated with a laser L, and a part of the bonding layer 5 is removed to remove a predetermined amount. No. 2 molded body 3, 30, 31, 300 is joined to obtain a gas permeation path in which a minute gap portion 5A is formed on the joining surface, and the removal amount for removing a predetermined amount of the joining layer 5 is 0. At a pressure of 1 MPa (G), By Umuriku speed is set so as to form a small gap portion 5A to be ^{1.0 × 10 -2 ~1.0 × 10 -5} Pa · m 3 / s, moisture hardly gas permeable by transmitting A good gas permeation path was formed. In this case, the minute gap 5A is formed on the surface of the second molded body 3, 30, 31, 300 so as to communicate with both end surfaces of the gas permeable bonded body 1. Alternatively, the bonding layer 5 may be formed on the surfaces of 2 and 21 so as to communicate with both end surfaces of the gas permeable bonded body 1. In this way, since the minute gap 5A is communicated in the direction of both end surfaces of the gas permeable joint 1, the gas permeable joint 1 constituting the hermetic container has both ends inside and outside the hermetic container. It functions as a gas permeation path for discharging the generated gas out of the sealed container. In this case, a resin bonding layer such as an epoxy resin material is used as the bonding layer 5, and although not shown, a method of removing a predetermined amount of the resin bonding layer with a masking jig when forming the resin bonding layer can be exemplified.

(Embodiment 2)

With reference to FIGS. 5-7, the structure of the gas permeable joined body which incorporated the flat 2nd molded object which made an explosion-proof valve or a safety valve an example in the 1st molded object similar to Embodiment 1 is demonstrated. .

In FIG. 7, the 2nd molded object 30 is flat, and the cyclic | annular joining layer 5 is formed in the surface with films, such as aluminum and a synthetic resin material. Although the shape of the 2nd molded object 30 illustrates a disk, a rectangular board may be sufficient. The bonding layer 5 is made of the same material as that of the first embodiment, and a predetermined amount of a part of the bonding layer 5 is removed to form a minute gap portion 5A. The removal amount for removing the bonding layer 5 by a predetermined amount is a pressure of 0.1 MPa (G) and a helium leak rate of 1.0 × 10 ^{−2 to} 1.0 × 10 ⁻⁵ Pa as in the first embodiment. It may be set so as to form a minute gap 5A that becomes m ³ / s. As shown in FIGS. 5 and 6, the second molded body 30 is interposed through the bonding layer 5 so as to cover the through holes 4 on the surface (the upper surface in FIG. 5) of the first molded body 2 having the through holes 4. Are heated and pressurized. The minute gap portion 5A joins the first molded body 2 and the second molded body 30 and communicates with the through-hole 4 at the joint surface, and the generated gas is passed through the through-hole 4 to form a minute gap portion. It becomes a gas permeation path which discharges 5A in the direction of an arrow. At this time, when a large amount of gas is generated exceeding the ability to discharge the gas from the minute gap 5A and the gas pressure increases, the second molded body 30 passes through the through holes 4 of the first molded body 2. It becomes the explosion-proof valve (or safety valve) 7 in which the second molded body 30 is broken so as to be opened.

(Embodiment 3)

With reference to FIG. 8 and FIG. 9, the structure of the gas permeable joined body incorporating the 2nd molded object of the shape which combined the column shape and flat plate shape which made an electrode end terminal an example is demonstrated.

8 and 9, the first molded body 2 constitutes a part of a closed container having a through hole 4 and is made of a metal material such as aluminum (including alloy). The through hole 4 has polyphenylene sulfide. A hollow cylindrical gasket 2A made of a synthetic resin material such as (PPS) resin or polypropyne (PP) resin is integrally formed. In the hollow of the gasket 2A, a second molded body 300 that is an electrode terminal 8 having a flat end face and a columnar portion from the center to the other end (lower end in FIG. 8) is disposed. The second molded body 300 is made of a metal material such as copper (including alloy) or aluminum (including alloy) so as to be the electrode terminal 8. Mercapto group, thiocarbonyl group, cyano group, isocyanate group, amino group, ammonium group, pyridinium group on the surface of second molded body 300 (surface bonded to first molded body 2 and surface bonded to gasket 2A) , An azinyl group, a carboxyl group, a benzotriazole group, a triazine thiol group, or the like, or a bonding layer 5 made of an adhesive thin film layer d made of a chemical treatment agent combined with these. The second molded body 300 is pressed into the hollow of the gasket 2A, and the second molded body 300 is disposed so as to be fixed to the gasket 2A via the bonding layer 5, whereby the gasket 2A is the first molded body. 2 and the second molded body 300 are electrically insulated. Further, a minute gap portion 5A obtained by removing a predetermined amount of a part of the bonding layer 5 on the surface that joins the second molded body 300 and the first molded body 2 and the surface that joins the second molded body 300 and the gasket 2A. Is formed. The removal amount for removing the bonding layer 5 by a predetermined amount is a pressure of 0.1 MPa (G) and a helium leak rate of 1.0 × 10 ^{−2 to} 1.0 × 10 ⁻⁵ Pa as in the first embodiment. It may be set so as to form a minute gap 5A that becomes m ³ / s. The minute gap 5A communicates with the inside of the sealed container at the joint surface where the gasket 2A integrally molded with the first molded body 2 and the second molded body 300 are joined, and is generated in the sealed container. The gas thus formed becomes a gas permeation path through which the minute gap portion 5A is discharged in the direction of the arrow.

(Sealed electrochemical device)

FIG. 10 shows a sealed electrochemical device using the gas permeable joined body of the sealed electrochemical device of the first to third embodiments.

In FIG. 10, the flat plate-shaped first molded body 2 is provided with a liquid stopper 6 and an explosion-proof valve (or safety valve) 7, and becomes a sealing plate which is a lid body in which a pair of electrode terminals 8 and 8 are arranged side by side. 1 shows a sealed electrochemical device in which a cylindrical or rectangular parallelepiped box-shaped case 10 with a lid is closed to form a sealed container, and this sealed electrochemical device is a capacitor, a lithium battery, or the like having an electrolytic solution 9. Inside the sealed container, the connection part 81 of the electrode terminal 8, the lead 91 electrically connected to the connection part 81, the electrode element part 90 electrically connected to the lead 91 and the electrolyte 9 are sealed and accommodated. ing. Thus, in a sealed electrochemical device such as a capacitor or a lithium battery having the electrode element portion 90 and the electrolytic solution 9, the electrolytic solution 9 is sealed so as not to leak out, and thus a charge / discharge cycle Repeatedly, left at high temperature, or the electrolyte solution 8 is decomposed by short circuit, overcharge, reverse charge, etc., and gas such as oxygen and carbon dioxide is generated, and the internal pressure rapidly increases due to accumulation of the gas. The sealing plate (first molded body 2) and the box-shaped case 10 that become the sealed container main body may rise or rupture. The part 5A is appropriately discharged out of the sealed container. Furthermore, when a large amount of gas is generated exceeding the ability to discharge the gas from the minute gap 5A and the gas pressure becomes high, the explosion-proof valve (or safety valve) 7 is operated to open the inside of the sealed container and release the gas. The container is discharged to prevent the sealed container from bursting.
(Embodiment 4)

FIG. 11 to FIG. 13 show a gas permeable joined body applied to a sealed electrochemical device that uses a first molded body that does not have a through-hole through which gas passes to form a sealed container.

11 to 13, the first molded body 21 and the second molded body 31 are a film of a synthetic resin material such as polyphenylene sulfide (PPS) resin or polypropyne (PP) resin, and a metal such as aluminum (including alloy). The outermost layer is composed of a synthetic resin film. The first molded body 21 is a rectangular flat plate on which an annular bonding layer 5 is formed (see FIG. 12). The second molded body 31 is formed with a bag-shaped open container having an annular flange 31 </ b> A at the edge, and the annular bonding layer 5 of the first molded body 21 is formed of the second molded body 31. An airtight container is formed by joining the first molded body 21 and the second molded body 31 together with the electrode terminals 8 described later so as to be disposed in the flange portion 31A. An electrode element portion 92 combined with an electrolyte is accommodated in the sealed container, and the electrode element portion 92 is electrically connected to a pair of electrode terminals 8 and 8 of a positive electrode and a negative electrode via a connection portion 81. And sealed. The pair of electrode terminals 8 and 8 are closely bonded by heating and pressurizing the first molded body 21 and the flange portion 31 </ b> A of the second molded body 31 through the bonding layer 5. Between the pair of electrode terminals 8, 8, a predetermined amount is removed so that a part of the bonding layer 5 communicates with the inside of the sealed container to form a minute gap 5 </ b> A. A removal amount for removing a predetermined amount of the bonding layer 5 is a pressure of 0.1 MPa (G) and a helium leak rate of 1.0 × 10 ^{−2 to} 1.0 × 10 10 as in the first embodiment. ^What is necessary is just to set so that the micro gap | interval part 5A used as ^-5 Pa * m < ³ > / s may be formed. In the minute gap 5A formed in this way, the generated gas is discharged from the inside of the sealed container in the direction of the arrow at the joint surface between the first molded body 21 and the flange 31A of the second molded body 31. It becomes a gas permeation path.

As described above, the gas permeable bonded bodies 1 and 11 are formed in a sealed container by bonding the first molded bodies 2 and 21 and the second bonded bodies 3, 30, 31, and 300 through the bonding layer 5. When forming a part of the sealed container, a small amount of the gap between the part of the bonding layer 5 connected to the sealed container by removing a predetermined amount so as to communicate with the sealed container. 5A is formed. Preferably, a part of the bonding layer 5 is irradiated with the laser L, and a part of the bonding layer 5 is removed to remove a predetermined amount. Helium leak rate is 1.0 × 10 ^{−2 to} 1.0 × 10 ⁻⁵ Pa · m ³ at a pressure of 0.1 MPa (G) on the joint surface with the second molded body 3, 30, 31, 300. Gas permeation with good gas permeability is difficult to permeate moisture by forming a minute gap portion 5A that becomes / s. What is necessary is just to set to the magnitude | size made into a road. Further, the minute gaps 5A may be formed at a plurality of locations in the bonding layer 5 to communicate with the inside of the sealed container.

The present invention is useful as a sealed electrochemical device such as a capacitor or a lithium battery having an electrolytic solution or a solid electrolyte.

DESCRIPTION OF SYMBOLS 1, 11 Gas permeable joined body 2, 21 1st molded object 3, 30, 31, 300 2nd molded object 5 Joining layer 5A Minute gap | interval part

Claims (3)

A sealed container is formed by forming a bonding layer on at least one of the first molded body and the second molded body and bonding the first molded body and the second molded body through the bonding layer. A predetermined amount is removed so as to form a member and a part of the bonding layer communicates with the inside of the sealed container, and the first molded body and the second molded body are bonded to each other, and a minute gap is formed on the bonding surface. A gas permeable assembly for a sealed electrochemical device, wherein the minute gap portion serves as a gas permeable path for discharging gas generated in the sealed container to the outside of the sealed container. The minute gap portion is a gas permeation path having a pressure of 0.1 MPa (G) and a helium leak rate of 1.0 × 10 ^{−2 to} 1.0 × 10 ⁻⁵ Pa · m ³ / s. The gas permeable joined body of the sealed electrochemical device according to claim 1, wherein the gas permeable joined body is a sealed electrochemical device. The first molded body has a through hole, the first molded body and the second molded body are bonded via the bonding layer to close the through hole, and the first molded body and A sealing body that is a constituent member of the sealed container is formed with the second molded body, and a predetermined amount is removed so that a part of the bonding layer is communicated with the through-hole, and the first molded body and the second molded body are removed. 3. The sealed electrochemical according to claim 1, wherein a minute gap is formed on a joint surface between the first molded body and the second molded body by bonding the molded body. Device gas permeable assembly.

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